1. Field of the Invention
The present invention relates to a testing method for a thin-film magnetic head that is to be performed while simulating the state of the thin-film magnetic head in actual operation, and to a jig used for the method.
2. Description of the Related Art
A magnetic disk drive has a recording medium to be driven to rotate and a thin-film magnetic head for writing data on and reading data from the recording medium. The thin-film magnetic head for use in the magnetic disk drive is typically in the form of a slider having a thin-film magnetic head element (hereinafter simply referred to as a head element) provided at a rear end thereof. In the magnetic disk drive, the slider is flexibly supported by a suspension so as to face toward the recording medium. In the magnetic disk drive, when the recording medium rotates, a lift is generated for the slider due to an airflow passing between the recording medium and the slider, and the lift causes the slider to slightly fly over the surface of the recording medium.
Typically, a head element includes a magnetoresistive element (that may be hereinafter simply referred to as an MR element) for reading and an induction-type electromagnetic transducer for writing. Examples of the MR element include a GMR (giant magnetoresistive) element utilizing a giant magnetoresistive effect, and a TMR (tunneling magnetoresistive) element utilizing a tunneling magnetoresistive effect. The induction-type electromagnetic transducer has a coil and a pole layer. The coil generates a magnetic field corresponding to data to be written on the recording medium. The pole layer allows a magnetic flux corresponding to the magnetic field generated by the coil to pass therethrough and generates a write magnetic field for writing the data on the recording medium. The coil generates heat upon being energized.
Some thin-film magnetic heads incorporate a heater for heating the components of the head element to make them expand so as to control the distance between the recording medium and an end face of the head element located in a medium facing surface that faces toward the recording medium.
In order to evaluate the life of a thin-film magnetic head or to evaluate a mechanical, electrical or electromagnetic change of a thin-film magnetic head caused by heat generated in the thin-film magnetic head, a test is performed on the thin-film magnetic head as required.
When a thin-film magnetic head is in actual operation, it has a characteristic that the medium facing surface is cooled by the airflow passing between the recording medium and the thin-film magnetic head while the coil or heater generates heat. When testing a thin-film magnetic head, it is therefore important to simulate the state of the thin-film magnetic head in actual operation, with the heat generation and cooling taken into account.
JP 2007-265493A discloses a testing method for evaluating the electromagnetic transducing characteristic of a read element that is performed by energizing a heater in such a state that a slider including the read element, the heater and a write element is attached to a suspension and made to fly over a rotating magnetic disk platter.
According to the testing method disclosed in JP 2007-265493A, however, it is not possible to simply test a thin-film magnetic head in a slider state, because the disclosed method requires that the slider be attached to a suspension and made to fly over a rotating magnetic disk platter.
Furthermore, the testing method disclosed in JP 2007-265493A can test only a single thin-film magnetic head (slider) at a time, and is therefore not suitable for testing a number of thin-film magnetic heads at a time.